How to add permission ?
No unregistered user may not be able to access in the category>>forum.
AdminCP -> Forums & Posts.
Click on category Forum en choose tab Permissions. Drag "view" permissions of groups that are not allowed to see the forum to the right column "Overview: Disallowed Actions". Do not forget to click "Save Forum Permissions" at the bottom of the page before you leave it.
Many times I forget to click "Save Forum Permissions", then I look why it still doesn't work. So, click "Save Forum Permissions"
